Resistor



Sept- 10, 1929- G. H. WHITTINGHAM 1,728,091

RESISTOR Filed DSC. 27, 1926 2 Sheets-Sheet l Sept 10, 1929- G. H. wHlTTlNGHAM 1,728,091

RESISTOR 2 Sheets-Shet 2 Filed Deo. 27. 1926 rigid structure Patented Sept. 10, 1929.

UNITED STATES PATENT OFFICE.

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Application filed December 27, 1928. Serial llo. 157,188.

The invention relates to a core for resistors used on high tension circuits. The core of the resistor is made of porcelain. As this material cannot be made in long pieces without 5 warping, it has heretofore been made in rel- 1'0 the present invention is to provide a core for the resistor composed of a plurality of rela-r tively short sections of porcelain, so inter-4 locked with one another that when the helix is wound upon the core'the latter will be a without a bar for supporting the sections. a

In my PatentNo. 1,648,871, dated Nov. 8, 1927 I have shown and described a resistor comprising a metal-supporting bar and a covering of insulating materialthereon, comprising a plurality of relatively short sections, each having a beveled end abutting against a like end of another section, so that the convolutions of the helix of resistance wire, wound on the covering, will cross the joints between the sections at an angle, and there are no crevi'ces into which the convolutions oft-he helix may slip. In the present invention, the short sections of insulating material are of the same design as ,the sections shown in theaforesad application, ,with additional features byl which the'various sections become interlocked against endwise or lateral movement, so that when the parts are held together by the resistance wire wound upon the core, the latter will form a rigid ,structure which does not require a bar to support its various sections.

40 In the accompanying drawing, which illustrates the invention,

. Fig.Y 1 is a plan view of a resistor made according to my invention, the core being partly broken away, and only parts ofthe helix being shown;

Fig. 2 is a similar view of a core, showing the same assembled upon a temporary supporting bar; .l j

Fig. 3 is-,a plan view showing the outer `surface of one-half of the core.;

Fig. 4 is a similar view showing the inner face of the other half of the core Fig. 5is a perspective view of one of the end sections of the core;

Fig. 6 is a similar view of one of the central sections; v

' Fig. 7 is a section on the line 7-7 of Fi 2; 2 Fig(i Sis a section on the line 8-8 of Fig.

i an a Fig. 9 is a section on the line 9-9 of Fig. 1.

Referring to the drawing, the core A of the resistor is composed of a plurality 'of semicylindrical sections of refractory insulating material, porcelain, one of the end sections a being shown in perspective in Fig. 5, and one, of the intermediate sections b being similarly shown in Fig. 6. Each end section has a narrow oove 1, extending centrally along its inner ace, from end to end of the section, and it also has two parallel grooves 2 and 3, at opposite sides of the oove 1, the grooves 2 and 3 preferably being semi-circular in cross section. In .these latter grooves are integral stops or shoulders 4 and 5, respectively,

v,which project above the inner face of the sec' tion and are adapted to iit within like grooves in other sections. One end of each end secf tion is at right an les tothe body of the sec- :tion and is prefera ly formed with a flange 6, andthe other end of the section is beveled or incli ed, as shown at? in Fig. 5. Each in" termediate section, as shown in Fig. 6, has both ends 8 and 9 beveled or inclinedat the same angle as the beveled ends of the end sections. Each intermediate section also has a central oove 1! and grooves 2'L and 3*, corresponding to thel grooves 1, 2 and 3 in the l end sections. Each intermediate section also has integral stops 10 and 11 in the groove 2 and stops 12 and 13 .in the groove 3, these ystops projecting above the faces of the sections. In building up the core, the sections are temporarily assembled upon a flat metal bar 14, Figs. 2 and 8, and this bar is afterwards withdrawn. A series of sections, as a, a2 and a3, Fig. 4, is assembled of the bar, this bar' entering the central grooves 1, 1. An opposing series of sections,

4 ig. 3, is then assembled on the opposite edge of the bar, and the sections in the two series, meeting face to face, form a cylinder, as illustrated in Fig. 8.

Fig. 4 shows end sections a and a2 and one intermediate section b', arranged end to end; and Fig. 3 shows an opposing series of sections, aa, b2 and a4, adapted to be assembled on the bar over the series shown in Fig. 4. In Fig. 3, which shows the outer sides of the sections, the stops or shoulders. on the sections are shown in dotted lines.

When the series of sections shown in Fig. 3 is assembled u onl the bar 14, opposite the series shown in ig. 4, the stops or shoulders on the several sections will be in the relation indicated in Fig. 2. The stops 10 and 12 on the section bf are staggered and the correspending staggered'stops 10a and 12a will lit against opposite sides of the stops 10 and 12. This engagement of the stops will prevent relative endwise movement of the opposed intermediate sections. The stop 11 on the intermediate section 3a will engage the rear end of the stop 5* on the end section aua and thus prevent endwise movement of the latter section, and the stop 11a on the intermediate section b2 will be located back of the stop 5 on the opposed end section a. Thus, both ofthe end sections a and as will be interlocked with the intermediate sections so that v the sections cannot be pulled apart. The stop 5 on the end section a2 willstand back of the stop 13 on the overlapping portion o f the intermediate section b2, and the stop 13 on thev intermediate section b will extend back of the stop 5 on` the opposed send section a?. Thus, the ends sections a2 and a* will also be interlocked with the intermediate sections to prevent relative endwise movement between these sections. The stops 4 and 4 in the end sections do not interlock with intermediate sections, .butthese stops, together with all of the other stops or shoulders, serve to hold the upper series of sections againt lateral movement with repect to the lower series when the bar 14 is removed from `the core.

After thesections have been assembled in the manner described, upon the metal bar, the wire helix c is wound upon the core.V Prior to the winding ofthe helix, the sections may be held together by removable clamps and as. the wire is wound upon thecore these clamps may be removed. It will be evident that the l winding of the wire upon the core will hold the sections'tightly together so that they cannot move apart radially. and as they are interlocked by the shoulders against relative longitudinal and lateral movement, the

on one edge finished resistor will be a rigid structure even after the metal bar is'withdrawn from the core.

Thus, a resistor of any desired length may be built up, having a core made entirely of porcelain. y The resistor may be supported out of contact with metal parts by insulators d, mounted upon a suitable frame and having prongs 15 which enter the grooves 2 and 3 in the end sections and abut against the stops or shoulders 4 and 4, as illustrated in Fig. 1. The convolutions, of the helix cross the joints between the sections at an angle and therefore these convolutions cannot slip into any'T crevices between the sections. The terminals e may be held upon the core by winding a few turns of the wire over the flanged bases of the terminals, as further explained and illustrated in my co-pending application previously referred to.

What I claim is:

1. A resistor comprising-a core and a wire coil wound thereon, said'core comprising two parallel opposing series of relatively short sections of refractorv material, held against onev another by s'aid coil, sections in one series overlapping section@ l *be other series and interlocking therewith to prevent relative endwise movement of the sections in one series with respect to the sections in the other series.

2. A resistor comprising a core and a wire coil wound thereon, said core comprising two parallel opposing series of relatively short sections of refractory material, held against one another by said coil, sections in one series overlapping sections in the other series and interlocking therewith to prevent relative endwise and lateral movement of the sections in one series with'q respect to the sections in the other series.

3. A resistor comprising a core and a wire coil wound thereon, said core comprising two parallel opposing series of relatively short sections of refractory material, held against .one anotherby said coil, the sections in each series arranged end to end and each section in one series overlappinsr the end portion of a 'seriesarranged end to end and each section in one series overlapping the end portion of a section in the opposing series, said overlapping portions having parts which interlock and prevent relative endwise and lateral movement between the sections. q

5. Aresistor comprising a core and a wire coil wound thereon, said core comprising two lll parallel opposing series of relatively short sections of refractory material, held against one another b said coil, the sections in each series having beveled abutting ends and each section in one series overlapping the end portion of a section in the opposing series, said overlapping portions having parts which interlock and prevent relative endwise movement between the sections.

6. A resistor comprising a core and a wire coil wound thereon, said core comprising two parallel o posing series of relatively short sections o refractory material, held against one another b said coil, the sections in each series having eveled abutting ends and each section in one series overlapping the end portion of a section in the opposing series, said overlapping portions having parts which interlock and prevent relative endwise and lateral movement between the sections.

7. A resistor comprising a core and a wire coil wound thereon, said core comprising two parallel o posing series of relatively short sections o refractory material, held against one another by said coil, each series comprising end sections and an intermediate section, the sections in each series arranged end to end and each section in one series overlapping the end portion of a section in an opposing section, the op osed intermediate sections having parts w ich interlock to prevent relative endwise movement ofsaid intermediate sections, and the overla ping portions of the sections in one series aving parts which interlock with the overlapping portions of the sections of the opposing series and preventv relative endwise movement between the sections of both series.

8. A resistor comprising a core and a wire coil wound thereon, said core comprising two parallel opposing series of relatively short sections o one another by said coil, each section eing hemispherical in cross section and havin spaced longitudinal grooves on its inner side, t e sections in one series overlapping sections in the opposing series, and eac section hav ing a shoulder in one of its groovesinterlocking with a shoulder in a groove in the overlapping portion of an opposing section.

9. LA resistor comprising a core anda wire coil wound thereon, said .core comp parallel opposing series of relatively short.

sections of refractory material, held aaeinst one another by said coil, each section ing hemis s a longitudinal grooves on its inner side, t e sections in one series overlappin sections in the opposing series, each section aving a stop in one of its grooves projecting above the inner face of the section and extending within the oove in an opposing section. 10. resistor comprising a core and a wire coil wound thereon, said core com rising two parallel opposing series of relatively, shortl rising two herical in cross section and having.

GEORGE H. wiiiTTINGHAM.

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